34 Account of Observed Forms of Larynx. 



Furnarius Vieill. [Opetiorhptchus Temm., ligulus Spix.) The first and second 

 half-ring's of the bronchi are united to one another, to form the lateral bases of the 

 tracheal larynx. These lateral bases are connected by one anterior and one posterior 

 strip of cartilage ; on the posterior face a bent cartilage is placed, in the furcation of 

 the trachea, between the two bronchi. On the first bronchial ring a long osseous pyramid 

 is so placed, that its base reaches to the second half-ring- of the bronchus. This bone 

 extends upwards, free, on the sides of the membranous portion of the trachea, as far 

 as the region of its firm portion. The processus vocalis is only connected to the trachea 

 by the muscles, which arise from the latter, and are fastened to the former. Furmrms 

 has two such muscles on either side, one anterior and one posterior; and the position 

 of them is the same in all the succeeding genera. These muscles arise from the lower 

 portion of the trachea, and are attached to the anterior and posterior edges of the 

 processus vocalis nearer its base. From its tip arises the nmsculus sternotrachealis. The 

 membranous portion of the trachea, in the tracheal organ of voice, again consists of 

 the transparent membranes of the larynx, and the extremely fine, and linear, though 

 osseous anterior and posterior half-rings, which are contained in its flat membranous 

 walls. These are only half-rings, and their ends are connected to the sides by the 

 elastic band, which reaches from the trachea to the bronchus. There are six or seven 

 such half-rings in the anterior and posterior walls. The membranous portion of the 

 trachea is contracted, and the vibrating half-rings brought closer together, when the 

 two muscles on either side of the processus vocalis, and consequently the bronchi, and 

 the lower end of the trachea, are raised". The nmsculi sternotracheales produce the 

 opposite result. 



I examined Furnarius rnfus Vieill. {Turdas hadius Licht. Doubl. Verz. 441) and 

 F. levcopus Sw. 



The genus Cinclodes Gray [Cillurus Cab.) is similar. I examined Cillurus nigro- 

 fumosus Cab. in v. Tschudi in Wiegm. Archiv. 1844 {Upucerthia nigrofumosa D'Orb.). 



So too the genus Anahates. I examined A. contaminatus Mus. Berol., A. adspersus 

 M. B., A. alhicoUis M. B. 



The base of the larynx consists of the last tracheal ring, which is cleft anteriorly, 

 and the commencement, i. e. the first and second half-rings, of the bronchi. On the 

 hinder face there is a large cartilage uniting the bronchi, as in Furnarius, and a similar 

 smaller one anteriorly, which fills up the cleft in tlie last tracheal ring. The six 

 vibrating and extremely fine half-rings of the vocal membrane of the trachea have 

 at their sides a large but membranous gap, and in it are wanting those bands, which 



